Device for recovering drinking water from condensate as well as a method and a deep-drawing die for production of said device

ABSTRACT

A device for recovering drinking water from condensate consists of a self-supporting moulded part  11  consisting of a transparent synthetic resin such as PET or PC, which is resistant to UV radiation. The moulded part  11  presents an open bottom area  16  with a collecting channel  15  on the edge side, with the collecting channel  15  presenting an inner wall  18  oriented towards the circumferential surface  12  and serving, at the same time, as floating aid, and with the moulded part  11  being provided with a pouring opening in its upper section  13 . For the manufacture of this device, a vacuum is created in a special deep-drawing tool not only in the region of the circumferential surface to be produced but also in the region of the collecting channel to be formed, and the moulded part is separated from a separated deep-drawing tool element outside the zone of the collecting channel.

The present invention relates to a device for drinking-water recoveryfrom condensate, as well as to a method of manufacturing this device anda deep-drawing tool for carrying through this method.

The present invention particularly involves a device suitable forwater-borne applications, specifically at sea, and applications ashorefor collecting water as condensate, that has evaporated under theinfluence of solar radiation. Within the general framework of thisenvisaged application, a seawater desalination, operated on solarenergy, is envisaged, too.

Mobile inflatable seawater desalination devices have been known alreadyfor cases of emergency in the marine, which comprise an inflatable PVCring as floating base and a separate conical transparent PVC sheet overthis floating base, which serves as condensation surface. There, thecondensate is collected between the outside of the ring and the insideof the cone, with the sheet cone, which is dimensionally unstable, beingmaintained in the required shape by means of supporting rods.

What must be considered to be a disadvantage in that known device is thefact that the sheets are easily damaged and may easily be perforated inparticular. Moreover, a structure including rods is extremelytroublesome and requires an appropriate assembly in order to avoidmalfunctioning. The manufacture of the individual parts of the device iscomparatively expensive and there are also disadvantages in terms ofhandling with respect to cleaning of the sheets due to theirflexibility. Apart therefrom the sheets can be exposed to mechanicalloads within limits only and are sensible to outside weather conditionssuch as wind and rain. Finally, the discharge of the collectedcondensate is inconvenient and problematic because the condensate mustbe poured out via the underside of the device while some condensate mayalso be lost.

The U.S. Pat. No. 3,415,719 discloses a foldable device for the recoveryof condensed water that is operated on solar energy, which consists ofan inflatable transparent plastic body in which a collector receptaclepermeable to water vapour is provided as bottom element for collectingthe condensate, which device is to be placed on a water body. Theaforementioned disadvantages apply substantially to this device, too,specifically the problems in terms of handling and dimensionalstability.

The document WO 00/03779 discloses a device for recovery of condensedwater, which comprises a conical bonnet whose lower end presents anintegral inward fold to form a collecting channel and for receiving abottom plate with an evaporating arrangement. This evaporating plate issurrounded by an additional buoyancy ring. In addition to theaforementioned disadvantages, the expensive manufacture of this devicewith an inflatable floating ring, the complex configuration of theevaporating plate, as well as their assembly to create a ready-to-usedevice must be considered to constitute a further disadvantage.

The present invention is hence based on the problem of providing adevice of the type outlined by way of introduction, as well as a methodof manufacturing same and a deep-drawing tool for carrying through themethod, which presents a comparatively simple structure and permits aneasy and unproblematic handling or manufacture, respectively, with ahigh efficiency.

In accordance with the invention, this problem is solved by therespective features in the Patent Claims 1, 18 or 19. Preferred featuresimproving the invention in an expedient manner can be derived from therespective dependent Claims.

Due to the inventive configuration of the device, definite advantagesare achieved in terms of manufacture, use and utilisation. Thebonnet-shaped, particularly conical or frusto-conical or pyramidal,moulded part expediently consists of a strong but flexible material suchas PET, PE, PP or PC. In this manner, a sufficient mechanical strengthis achieved to resist damage that could be caused by pointed objects.Moreover, there is no deformation under the influence of wind. Thefunctional integrity is therefore not impaired by exterior weatherconditions such as rain, wind and the like.

Due to the geometry of the moulded part, the invention provides theexpedient feature that the condensate-collecting channel performs thefunction of a floating body at the same time when the device is employedon water surfaces. An additional floating body or buoyancy ring cantherefore be dispensed with. The device can be expediently moulded as anintegral part and in series so that it can be manufactured at a lowprice, which is particularly expedient for an application in developingcountries.

The fact that the moulded part does not include a bottom with anevaporating section must be considered to be a further advantage. As aresult, problems with algae and the formation of crusts are not created.The device is simple to clean and is ready for use immediately, withoutbeing inflated and without a supporting structure.

In accordance with another embodiment of the invention, a pouringopening is provided at the tip of the moulded part for pouring out thecondensate. Being appropriately placed, this opening cannot be soiled,or water cannot flow out in an undesirable manner.

In correspondence with an expedient further embodiment of the invention,the pouring opening can be closed with a screw plug and can hence beintuitively used as a drinking bottle. At the same time, the device canalso be used as rain-collecting receptacle after it has been turnedupside down, due to its dimensionally stable design.

Finally, a further advantage of the provision of a preferably closabledischarge opening in the upper section of the moulded part, particularlyat the tip of a cone or a pyramid, resides in the fact that the mouldedpart as a whole must be tilted by 180° for pouring out the condensate.The quantity of the recovered drinking water can even be increasedexpediently by the condensate drops present on the inner wall, which canalso be poured out.

According to a further embodiment of the invention, the moulded body ismanufactured from two moulded parts disposed on top of each other, whichare adapted to be fastened on each other in the bottom zone. As aresult, a so-called double-wall structure is obtained, which permits theachievement of a particularly high efficiency in condensate recovery. Tothis adds the fact that any condensate dripping prematurely off theoutside skirt is collected at the inner wall of the channel, whichextends in parallel with the outside skirt, and does not drip off intothe free bottom area. Another expedient aspect of the raised inneropening is the appropriate protection from the undesirable penetrationof waves on which the device is floating.

All of the embodiments of the inventive device present a furtheradvantage when the inner side of the circumferential surface is providedwith a non-fogging coating and when its outside surface is resistant toscratching.

Apart from the simple manufacture, which involves only little waste,also the provision of holding openings is expedient for the devicecomposed of two parts, particularly deep-drawn elements, which openingshave the two functions of holding handles and of anchoring or fasteningthe device. Adhesives or other connecting means with bacteria- andalgae-preventing substances are expediently provided for bonding the twomoulded parts.

In all the embodiments of the inventive device, filter cartridges may beinserted in the zone of the pouring opening in order to filter out sand,dust, bacteria, etc. and/or mineral cartridges may be provided for theaddition of minerals. When the bonnet surface, particularly the surfaceof the cone, is slightly vaulted, a higher stability is achieved. Eyesprovided in the zone of the pouring opening below the collar contributeto the dimensional stability and are extremely resistant to tearing upin an expedient manner.

Moreover, in correspondence with another embodiment of the invention,the outside skirt may be enlarged by moulded-in zones and/or shapedraised sections, particularly in the form of grooves or corrugations, inorder to enlarge the condensation area and to achieve better cooling. Anadditional heat-collecting effect may additionally be achieved with acloth of material that is permeable to vapour, which cloth is stretchedover the underside of the moulded body and prevents, at the same time, acontamination by the washing of the waves. Moreover, additional closableopenings may be provided for drainage in the zone of the collectingchannel.

In conclusion, the inventive device provides for a simple and intuitivehandling, with the condensate-collecting channel not only providing anappropriate holding handle but also a floating aid, with a simpledesign. The device does not require maintenance, can be stacked and isready for use immediately without any further attachments orsuperstructures.

Due to the envisaged moulded shape, the moulded bodies can also besafely stacked without any problems whilst the stacks so formed are easyto transport by means of a supporting rod projecting through the openpouring openings.

The inventive method of manufacturing a device for drinking-waterrecovery from condensate in correspondence with the features defined inclaim 18 provides for a special vacuum treatment for the deep-drawingoperation by additional lateral exhaustion in the zone of the collectingchannel to be formed, as well as for a separation of the moulded partfrom a separated deep-drawing tool element outside the zone of thecollecting channel. Due to the special additional exhaustion in the zoneof the collecting channel to be formed, it is possible to shapeexpediently rearwards engaging sections of the moulded part completelyin correspondence with the desired shape while the finished moulded partis simple to separate subsequently from a separated deep-drawingelement. This method allows for an extremely simple and efficientproduction of devices, particularly devices with rotational symmetry.

The deep-drawing tool, which is additionally provided for carryingthrough the method presenting the features defined in claim 19, isexpediently formed to comprise a principal section and an attachmentsection, which permits the moulding of the envisaged collecting channelat the edge side with a constant wall thickness and a constant outsidecontour. As a result, a rearwards engaging zone of the moulded part iswell moulded, which would otherwise not be sufficiently considered inthe application of a vacuum in the zone of the principal section. Theair suction bores provided for forming the collecting channel arepreferably formed in the attachment section and connected to suction airducts in the principal section.

In correspondence with a preferred further embodiment, the attachmentsection presents a peripheral rounded mould edge for forming an inneredge of the collecting channel, with the attachment section preferablycomprising a stop for a separating tool that is preferably formed on therounded mould edge.

In correspondence with another embodiment of the invention, theattachment section has a bipartite configuration in order to be able toprovide a manufacture of the suction air ducts, a suction plane and ofsuction air ducts in the attachment section.

In the following, the invention will be explained in more details withreference to the attached drawings wherein:

FIG. 1 is a perspective side view of a first embodiment of an inventivedevice;

FIG. 2 is a schematic illustration of 4 devices according to FIG. 1,which are stacked on top of each other;

FIG. 3 shows another embodiment of the invention for explaining theprinciple of operation;

FIG. 4 illustrates the embodiment according to FIG. 3 in a schematicsection in a condition in which the condensate is poured out;

FIG. 5 is a view of another embodiment of an inventive device in which ablack cloth permeable to water is stretched over the bottom area toprovide protection from the washing of the waves and for achieving agreater evaporation heat;

FIG. 6 shows a schematic view of a further embodiment of the invention;

FIG. 7 is a view of the device according to FIG. 6 from below;

FIG. 8 is an illustration of the assembly of the device according toFIG. 6;

FIGS. 9 to 12 show various embodiments of devices presenting differentgeometries of the outside wall;

FIGS. 13 to 15 illustrate a schematic perspective side view, a view frombelow and a sectional view along the line XIII-XIII in FIG. 13;

FIGS. 16 to 18 show various geometries of collecting channels adapted tobe stacked;

FIGS. 19 and 20 are schematic views of steps for the manufacture of anembodiment of an inventive device;

FIG. 21 shows a schematic sectional view taken through an embodiment ofan inventive deep-drawing tool for the manufacture of a devicepresenting rotational symmetry;

FIG. 22 is a partial sectional view at an enlarged scale in the upperleft area in FIG. 21 for the illustration of air suction bores; and

FIGS. 23 to 27 illustrate individual steps in the manufacture of oneembodiment of the inventive device, using an inventive deep-drawingtool.

FIG. 1 illustrates a first embodiment of an inventive device forrecovering drinking water from condensate. The device 10 consists of aconical moulded part 11 presenting a circumferential surface 12 thatextends from an upper section 13 of the moulded part to a lower section14. The moulded part 11 is of rotational symmetry and consists of atransparent synthetic resin such as PET and PC.

In the lower section, an inwardly projecting collecting channel 15 isintegrally formed on the edge side on the moulded part 11, which serves,at the same time, as floating aid. The collecting channel 15 surroundsan open bottom area 16 that is formed by the upper edge 17 and the innerwall 18 of the collecting channel 15. The inner wall 18 of thecollecting channel 15 extends approximately in parallel with thecircumferential surface 12.

A drainage opening 19 is provided in the lower section of the collectingchannel 15 for discharging the condensate in its entirety, which can beclosed by means of a closing element not illustrated here. A pouringopening 20 is formed in the upper section 13 of the moulded part 11,which comprises a collar 21 on the outside as well as a threadedtubulure with a screw-on lid 22 as closing element. Additional lateralintegrally formed parts 23 are moulded between the collar 21 and thecircumferential surface 12 as well as upper integrally formed parts 23′on the cover, which serve to increase the stability in the upper sectionand serve as holding handle and for additional attachment. In thesimplest basic form of the device according to FIG. 1, the device hasonly a configuration as roughly indicated in the stacked form in FIG. 2,with the stack of moulded bodies 11 according to FIG. 2 presenting anextreme dimensional stability and offering the possibility to pass a rodtherethrough, after removal of the screw-on covers 22, for simpletransportation. FIGS. 2 and 3 serve to explain more details of thehandling of one embodiment of the inventive device. In variation fromthe embodiment shown in FIG. 1, this embodiment comprises a filtercartridge 24 in the zone of its pouring opening 20 while the inner wall18 of the collecting channel is configured to extend in the directiontowards the open bottom area as a peripheral protective edge 25 thatserves as return stop for salt and waste water, as is schematicallyroughly indicated in FIG. 4 in the pouring condition.

As is illustrated in FIG. 3, the moulded part 11 is disposed either on amoist ground or on the surface of a water body. Under the influence ofsolar heat, the water is caused to evaporate in the zone of the freebottom area, with the water vapour depositing on the inner surface ofthe circumferential surfaces 12 in the form of a condensate and flowingdown along the circumferential surface up to the collecting channel 15under the influence of gravity. When a sufficient quantity of condensatehas accumulated in the collecting channel 15 the moulded part 11 isseized by its upper section 13 and turned upside down so that the wateraccumulated in the collecting channel will flow out through the pouringopening 20 from which the cover 22 has been removed before. With aswinging movement of the moulded part, the remaining condensate quantitythat has not yet flown down into the collecting channel 15 can beexpediently collected and poured out, too.

In the embodiment shown in FIG. 5, the inner wall is shown to present astraight surface, in distinction from the schematic view in FIGS. 3 and1, with the lower section of the moulded part 14 being flared in anappropriate form to the outside at the side of the edge for receivingcloth attachment means. The reference numeral 26 identifies a blackcloth stretched over the free bottom area 16, which cloth is permeableto water and serves as protection against the washing of the waves andto achieve a higher evaporation heat.

The FIGS. 6 and 7 are a schematic side view and a view from below of adouble-walled moulded part 11′ that consists of a lower moulded part 27and an upper moulded part 28, as is shown in FIG. 8. The upper mouldedpart, and likewise the lower moulded part, is configured as a deep-drawnelement and consists of a conical section that comprises anapproximately square bottom section at its lower end, which extends inthe lateral direction. The lower moulded part 27 has an equallyapproximately square bottom plate from which rises a frusto-conicalintegrally moulded part in the centre, which constitutes the inner wall18 of the collecting channel 15. As can be seen in FIG. 6, the innerwall 18 and the outside skirt 12 extend approximately in parallel almostinto the upper section 13 of the moulded part 11′. In operation of thedevice, condensate accumulates in the comparatively wide collectingchannel 15 that is formed between the inner wall 18 and the outsideskirt 12. The reference numeral 29 identifies continuous elongate holesserving as holding handles and as opening for fastening the device.

According to the illustration in FIG. 8, the upper moulded part 28 iscentrally placed on the lower moulded part 27 and bonded there orfastened by appropriate locking means for the manufacture of the deviceaccording to FIGS. 6 and 7, with the holding openings 29 being alignedin both bottom sections. The two moulded parts 27 and 28 may also beconnected to each other by means of a bacteria- and algae-preventingadhesive or silicone, respectively.

FIGS. 9 to 12 show various geometries of the outside wall of the mouldedbody 11, with additional integrally moulded parts such as the collar,the holding handle and the draining opening being omitted forsimplification. According to FIG. 1, the device comprises a conicalmoulded part whilst according to FIG. 10, the circumferential surface isvaulted to the outside in the manner of a bonnet. This furnishes afurther improvement of the stability. The configuration according toFIG. 11 is another possibility, with the circumferential surfacepresenting a shape similar to a hemisphere. The pyramidal configurationof the circumferential surface according to FIG. 12 provides for amaximum utilisation of the area.

In FIG. 13, the fact is schematically indicated in a device according toFIG. 11, that the circumferential surface may be enlarged by azigzag-shaped design including grooves for an enlargement of the surfaceand in order to permit a better control of the down flow of thecondensate drops. It is also possible to provide some other integrallymoulded-in guiding elements instead of the illustrated grooves 30, whichextend from the upper section 13 to the lower section 14 of the mouldedbody 11.

FIG. 14 shows a view from below of the device according to FIG. 13, andFIG. 15 roughly indicates the sectional profile extension along the lineXV-XV in FIG. 13 in a schematic form.

The FIGS. 16 to 18 illustrate various geometric shapes of collectingchannels for reliable and safe stacking of moulded bodies 11. In thelower section of the circumferential surface 12 as shown in FIG. 16 aperipheral moulded-in section 31 is provided that serves to receive asection 32 of the collecting channel 15 having a complementarycurvature.

According to FIG. 17, the lateral shaping of holding sections in amanner similar to the embodiment of according to FIG. 5 ensures that thedevices can be stacked in a reliable manner in the precise positionbecause here the lower surface 33 of the upper moulded body rests on theupper horizontal surface 34 of the lower moulded body.

FIG. 18 shows a further embodiment that provides for proper stacking ofthe moulded parts 11, wherein the inner wall 18 extends in parallel withthe circumferential surface 12 and is supported like a sheet.

For the manufacture of a device according to the embodiment illustratedin FIG. 5, the FIGS. 19 and 20 illustrate the appropriate steps ofoperation. FIG. 19 is a schematic view of a blow-shaped moulded partwithout a collecting channel. The moulded part 11 is provided with anopen section 35 tapering in a conical shape in a downward direction andhaving a bottom part that is subsequently cut away. As is illustrated inFIG. 20, then the section 35 is swung in after heating or tilted upwardas inner wall 18.

Now an embodiment of the inventive deep-drawing tool as well as themethod of manufacturing a device for recovery of drinking water fromcondensate will be explained in more details with reference to FIGS. 21to 27. FIG. 21 illustrates a schematic section taken through adeep-drawing tool 32 of rotational symmetry, which consists of aprincipal section 33 and an attachment section 34. In the principalsection 33, a cavity 35 for forming the wall section of a bonnet-shapedmoulded part, a moulded-in zone 36 for a pouring opening of the mouldedpart, lateral suction ducts 37, which lead from a suction cavity 38provided in the lower section of the principal section 33 to theattachment section 34, as well as a peripheral seal 39 are illustration,which is disposed in a recess 40 that is provided on the upper side of aperipheral edge section 41 at the upper end of the principal section 33.The edge section 41 extends up to a shoulder 42 that constitutes abearing surface for the attachment section 34. Like in FIGS. 19 and 20,the line A-A identifies the axis of symmetry or rotation, respectively,of the moulded body to be produced.

FIG. 22 is an enlarged sectional view of further details in the area ofthe left upper section of the deep-drawing mould 32. Here, air suctionbores 43 to 45 can be seen particularly clearly, which open into thezone of the collecting channel to be formed in the moulded part. Here,the suction bores 43 are still formed in the principal section 33 andopen directly into the annular suction duct 37 whilst the ducts 44 and45 lead to the air suction duct 46 or to a suction cavity 47,respectively, which is connected to it. For reasons of manufacturingtechnology, here the attachment section 34 is formed with a principalsection 48 and a cover-shaped annular part 49 that closes the suctioncavity 47 at the top. The principal section 48 is provided with aperipheral rounded mould edge 50 that has a finger-like cross-sectionalarea in the sectional view of FIG. 22. The reference numeral 51identifies a stop moulded in the mould edge for a separating tool. Thisstop serves to separate the moulded part from the attachment part 34after removal from the conical funnel or cavity 35, respectively, of themould. The outside contour of the mould edge 50 is rounded so that asmuch material as possible can be drawn into the interior space in thezone of the collecting channel to be produced on the edge side of themoulded part during the deep-drawing operation, without tearing thematerial.

The inventive method will now be described with reference to theschematic views in FIGS. 23 to 27 in more details. In the startingposition according to FIG. 23, in a first step of operation, a heatedsheet 52 made of a thermoplastic transparent synthetic resin with a sealon the edge side is placed on the schematically illustrated deep-drawingtool 32. Then, a vacuum is applied in the deep-drawing tool 32 forshaping the sheet 52, with the sheet 52 being shaped into thedeep-drawing tool 32 according to FIG. 24 and then according to FIG. 25,whilst the vacuum being extracted through the opening 36 (FIG. 21) ofthe principal section 33 as well as through the air suction bores 43 to45, which are explained in FIG. 22, in the zone of the collectingchannel to be formed on the edge side of the moulded part.

According to FIG. 26, then the cooled moulded part is removed from theprincipal section 33 of the mould, together with the attachment section34, and in the last step, the moulded part is then separated along thestop 51, which furnishes, on the one hand, a section 53 of the mouldedpart and, on the other hand, the finished moulded part 54, both detachedfrom the attachment part 34.

1. Device for recovering drinking-water from condensate, comprising abonnet-shaped self-supporting moulded part made of a transparentsynthetic resin such as PET or PC, which is resistant to UV radiation,said moulded part comprising in its lower section an open bottom areawith a collecting channel on the side of the edge, said collectingchannel having an inner wall oriented towards said circumferentialsurface, and said moulded part having a pouring opening in its uppersection
 2. Device according to claim 1, wherein the inner wall of saidcollecting channel presents a section extending approximately inparallel with a conical circumferential surface.
 3. Device according toclaim 1, wherein said upper edge of said inner wall of said collectingchannel is shaped in a direction towards the open bottom area.
 4. Deviceaccording to claim 1, wherein said pouring opening is disposed to extendcoaxially relative to the centre axis A-A of said moulded part. 5.Device according to claim 1, wherein a removable cap is provided forsaid pouring opening.
 6. Device according to claim 5, wherein said capis configured as a screw cap that can be screwed onto a threaded sectionon said pouring opening.
 7. Device according to claim 1, wherein atleast one moulded element is formed for holding and supporting. 8.Device according to claim 7, wherein a moulded holding element isdesigned as collar.
 9. Device according to claim 1, wherein a filterand/or mineral-adding means can be inserted into said pouring opening.10. Device according to claim 1, wherein the angle of inclination ofsaid circumferential surface of a moulded body having conical orfrusto-conical shape amounts to roughly 30°.
 11. Device according toclaim 1, wherein said circumferential surface of said moulded body isvaulted to the outside.
 12. Device according to claim 1, wherein theinner side of said circumferential surface presents surface-enlargingmoulded-in and/or moulded guiding elements that extend from the uppersection to the lower section of said moulded body.
 13. Device accordingto claim 1, wherein said moulded body is made of two moulded partsdisposed one on top of the other, which are adapted to be fastened oneach other in the respective bottom zone.
 14. Device according to claim13, wherein said upper moulded part presents the outer skirt and a flatbottom section whilst said lower part presents a flat bottom section andan inner wall of said channel.
 15. Device according to claim 13, whereinholding openings are provided on at least one bottom section.
 16. Deviceaccording to any of the claims 13 wherein the side of the inner wall ofthe groove, which faces said flat bottom area, is provided with anon-fogging coating.
 17. Device according to claim 1, wherein a blackwater-permeable cover is provided for said open bottom area.
 18. Methodof manufacturing a device according to claim 1, comprising the followingsteps of operation: (a) arranging a heated sheet of a thermoplastictransparent synthetic resin with a sealing on the edge side on adeep-drawing tool; (b) applying a vacuum in said deep-drawing tool inthe zone of the circumferential surface to be formed on said mouldedpart and additionally in the zone of the collecting channel to beformed; (c) removing the moulded part from the mould together with adeep-drawing tool element that is located in the zone of the collectingchannel to be formed; and (d) separating the moulded part from theseparated deep-drawing tool element outside the zone of said collectingchannel.
 19. Device according to claim 1, wherein the device is producedby deep-drawing by means of a deep-drawing tool, which comprises aprincipal section, in which a cavity is provided for forming the wallsection of a bonnet-shaped moulded part, preferably with a moulded-inzone for the pouring opening, and an attachment section that is providedfor forming the zone of said collecting channel on the edge side of saidmoulded part, with at least said attachment section comprising airsuction bores for forming said collecting channel of said moulded part.20. Device according to claim 19, wherein said attachment sectioncomprises at least one suction air duct that is connected to said airsuction bores.
 21. Device according to claim 19 wherein said attachmentpart comprises a peripheral rounded mould edge for forming an edge ofsaid collecting channel.
 22. Device according to claim 19, wherein saidattachment section comprises a stop for a separating tool.
 23. Deviceaccording to claim 22, wherein said stop is formed on said rounded mouldedge.
 24. Device according to claim 19, wherein said attachment sectionhas a bipartite configuration.